Add a swirl of oil to a heavy bottomed 4-quart pan or pot. Heat over medium flame until shimmering.
Add the onions, and sauté until golden and slightly tender. Add the garlic, tomato paste, and tomato puree. Give it a good stir. Stir in the lentils, salt, paprika, cumin, thyme, and half the cilantro. Add 1 cup of water, and bring to a boil over medium-high.
Reduce to a simmer, and cook, stirring occasionally, until the lentils are tender, about an hour, adding more water (1/4 cup at a time), as needed. The cooking time and amount of water will vary depending on the age of the lentils (i.e. how much they need to be hydrated).
To serve, stir the vinaigrette into the pot. Ladle the chili into deep bowls. Garnish with remaining cilantro, and enjoy!